The isoelastic, noncemented total hip arthroplasty. Preliminary experience with 400 cases

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Clinical Outcomes Research

Background:

• Cementless total hip arthroplasty (THA) is a common procedure for hip joint replacement.
• Polyacetyl femoral components offer potential advantages in THA due to their material properties.
• Evaluating early clinical and radiological outcomes is crucial for novel implant designs.

Purpose of the Study:

• To assess the early clinical and radiological outcomes of cementless isoelastic THA using polyacetyl femoral components.
• To identify and address any complications or failures associated with the femoral component design.
• To compare the effectiveness of different generations of femoral components in THA.

Main Methods:

• Prospective observational study of 400 patients undergoing cementless THA.
• Independent observer assessment with a minimum two-year follow-up.
• Clinical evaluation of patient satisfaction and functional outcomes.
• Radiological assessment for component loosening, subsidence, and alignment.

Main Results:

• 97% of surviving patients attended review; 92% reported good/excellent outcomes.
• Low complication rates: 1.6% infection, 0.8% revision for loosening/dislocation.
• Early subsidence/varus tilt with second-generation components resolved with third-generation designs.
• Third-generation components showed excellent clinical and radiological results with reduced gait support needs.

Conclusions:

• Cementless isoelastic THA with polyacetyl femoral components demonstrates encouraging early results.
• Improvements in femoral component design (third-generation) have overcome initial challenges.
• Longer-term follow-up is necessary to confirm the long-term effectiveness and durability of this prosthesis.